Choral risers are used in theatres, schools, auditoriums, and the like for presenting performances by singing groups. Usually the need for the risers is temporary, as the stage or auditorium is used for multiple purposes. Risers therefore have been developed which consist of a number of sections which can be placed side-by-side to make as large a riser as is needed for a particular performance, and which sections can be disassembled or folded and moved to a storage area when not needed. Of course, efficiency in assembly and disassembly is an important feature for a riser of this type, as is stability of the riser in its use configuration. Various types of risers have been developed in the prior art, although none completely meet this need.
It is customary to provide a riser setup on a stage with a straight center portion and side portions which angle inwardly toward the director or audience. In order to provide flexibility in accommodating different singing group sizes, it is desirable to have a single type of stage section which can be easily adapted to straight line side-by-side relationship with another section, or to angled relationship to another section. This is generally accomplished by providing riser steps of different widths and with angled sides, and providing means for changing positions of the steps on the riser. In one orientation, referred to herein as the forward orientation, the widest step is at the top position at the back of the section and the narrowest step is at the front at the lowest position, so that the riser section forms a generally trapezoidal shape, narrowing towards the front. In a reverse orientation, the narrowest step is at the top and the widest is at the front, so that the orientation of the trapezoidal shape is reversed. Adjacent sections in the forward orientation can be placed side-by-side to form an angle to bring the side portions inward. A forward orientation and reverse orientation section can be placed side-by-side in a straight line position, which is useful, for example, for the center portion of the stage setup.
Several problems can occur with reconfigurable riser sections of this type. Since the step portions are removable, attaching and locking means must be provided for securing the step portions to the riser sections. In order to save time in setting up the risers, the locking means must be simple and quick to operate. At the same time, they must be very secure and positive in operation to minimize the possibility of a step not being properly secured, which of course would present a hazard to the persons subsequently using the riser.
It is also important to provide means for securing adjacent stage sections to one another in a stage setup so that they will not move or open up a gap as they are being mounted or dismounted by the persons who will use the riser. It is also important that this type of lock be simple to use and secure in its action, but this is complicated by the fact that the locking system must be workable regardless of whether adjacent stage sections are in forward or reverse configuration.
It is customary to provide a guardrail along the back of each stage section, so that persons standing on the top row cannot accidentally fall backward off the stage. The guardrail should of course be as wide as the step in the top or back position on the stage. However, when a stage section is converted for reverse configuration, as described above, a narrower step ends up at the top position of the stage section, and this means that the guardrail is much wider than the top step, so the sides of the guardrail will interfere with the sides of guardrails of adjacent sections. To overcome this problem, the prior art provided for disassembly and removal of the outer end portions of the guardrails when a stage section is in the reverse configuration. However, this is undesirable since it requires extra operations in setting up and taking down the stage and the possibility that the removed guardrail sections will not be put back on properly.